The NHLBI Electron Microscopy Core Facility has supported projects using the following techniques in the past year: 1. Fixation, embedding, ultra-thin sectioning and transmission EM digital imaging of tissues and cells. 2. EM immunocytochemistry, including immunogold localization of proteins and other antigens within and on the surface of cells by pre-embedding techniques. 3. Negative staining of large proteins, polymers and supramolecular structures as well as lipid and membrane vesicles for transmission EM imaging. 4. Fixation, critical point drying, sputter-coating and scanning EM digital imaging of small organisms, organs, tissues and cells, as well as other materials such as artificial matrices. 5. Platinum carbon replicas of extracted, critical point dried cytoskeletons In the past year, we have supported 32 projects for 22 principal investigators in the NHLBI/DIR: Stewart Levine, James Shelhamer: Autophagy in leukotriene D4-treated mouse macrophage cell line. Robert Kotin: Characterization of AAV preparations for in vivo gene transfer;Course of AAV formation in baculovirus-infected insect cells. Cecilia Lo: Ultrastructure of cilia in humans with ciliary dyskinesia;Cilia ultrastructure in cardiac development mutants;Developmental defects related to sonic hedgehog signaling in cilia mutant mice. Rosa Puertollano: Regulation of mucolipin-1 induced lysosomal storage granule accumulation in Hela cells by LAPTM4a and 4b; Immunogold localization of novel mucolipin-containing organelles in cultured epithelial cells;Endosome and lysosome regulation by PI-4,5-P-4 Phosphatase Type I. Toren Finkel: Ultrastructural changes resulting from conditional knockout of ATG7 in pancreatic beta cells and skeletal muscle;Mitochondrial morphology in thymocytes of Bmi KO mice. Joel Moss: Lysosomes in liver of ARD1 knockout mice and cell lines. Robert Adelstein: Myocardium ultrastructure in myosin IIb conditional knockout mice;podocyte effacement in myosin IIa conditional knockout mice Nico Tjandra: Virus budding in internal compartments of transfected Cos cells Claire Waterman: Characterization of a synthetic surface for cell adhesion studies;Interaction of cells with 3D collagen gels on acrylamide. Jay Knutson: Characterization of gold and silver nano-particles;Gold nano-particle penetration into tissue slices. Mark Knepper: Immunogold localization of aquaporin channel redistribution in cultured epithelial cells. Jennifer Lee: Characterization of liposome-protein interactions;polymerization of amyloid proteins Howard Kruth: Macrophage processing of LDL. Alan Remaley: Micro-RNA binding to HDL. Julie Donaldson: Monocilia in an epithelial cell line. Maurice Burg: Cytoplasmic membrane dynamics during hypertonic stress in Hela cells. Michael Sack: Mitochondrial morphology in Pink 1 knockout mice. Paul Hwang: Mitochondria in mutant human myoblast cell lines. Neal Epstein: Characterization of stem cells derived from skeletal muscle. Yosuke Mukoyama: Interaction of developing blood vessels with nerve in embryonic mouse skin. Hong Xu: Eye structure in Drosophila mutants. Han Wen: Characterization of diffraction gratings for phase contrast X-ray imaging.